Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
tang hoa » hang hoa, tang ha, tang ho
hanh tai » thanh tai, hang tai, han tai
hoa hoi » khoa hoi, hoa hoc, hoa doi
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
tai cua » thai cua, tai cuc, tri cua
sach 2 » sach y
sach 7 » sach y
he nam » nghe nam

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((sach 7) OR (sach 2)) tang hoa hoi. hieu ((he nam) or (ha nam)) thuc va hanh tai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((sach 7) OR (sach 2)) tang hoa hoi. hieu ((he nam) OR (ha nam)) thuc va hanh tai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((sach 7) OR (sach 2)) tang hoa hoi. hieu ((he nam) or (ha nam)) thuc va hanh tai cua triet".
• Adding a wildcard symbol may retrieve word variants: doc ((sach 7) OR (sach 2)) tang hoa hoi. hieu ((he nam) or (ha nam)) thuc va hanh tai cua triet*.